Treatment of cotton fabrice.



UNITED STATES PATENT OFFICE.

OSCAR KLAUSER, 0F HERISAU, SWITZERLAND, ASSIGNOIB, TO THE FIRM OF AKTIEN- GESELLSCHAFT GILANDER, OF HERISAU, SWITZERLAND.

TREATMENT OF COTTON FABRICS.

No Drawing.

To all whom it may concern:

Be it known that I, OSCAR KLAUsnR, a

It is a wellaknown fact that if treated with sulfuric acid of at least 50%-B., ordinary cotton or cotton already mercerized will assume a parchment-like appearance by becoming transparent and somewhat stifi. These qualities may be intensified by submitting the stretched fabric to asubsequent treatment with lye of 2530 Bi' Now, if sulfuric acid of a lower concentration than 50% B. is used at normal temperature, e. 9., between 0 and 15 centigrade, the effect on the fabric will be far less pronounced, only a slight, if any, transparency being imparted to the cotton. In this case the action of the sulfuric acid will be a purely mercerizing one. (See Thomas and Prevost, British Patent No. 20714 of 1896). According to German Patent No. 129883 (Thomas and Prevost) the action of weaker sulfuric acid may be intensified by subsequent alkali-treatment, but even then only a comparatively low degree of transparency can be attained.

I have discovered that sulfuric acidof less than 501} B. (measured at 15 C. above zero) has an entirely new effect on cotton, if used at a temperature of not more than 4 below zero. If such cold sulfuric acid is employed, a subsequent treatment with lye.

least five seconds or cold sulfuric acid of 49 B. through a period of several minutes, and if subsequently the mercerizing action of a lye is applied-the latter being preferably also at a low temperature, about 0 C.then

the cotton thus treated will receive a transparant appearance.

By varying the length of time of dipping the cotton, and the temperature and concentration of the sulfuric acid employed, it is Specification of Letters Patent.

Patented Mar. 5, 1918.

Application filed August 12, 1916. Serial No. 114,620.

possible to obtain fabrics of a desired degree of transparency. Owing to the very low temperature of the sulfuric acid, it is possible to keep the cotton in contact with it for a period of ten minutes and more, so

that there is sufficient time for the acidto thoroughly soak into the cotton fiber, 'so that a more uniform transparency is ob tained than with the use of sulfuric .acid of 50% B. at normal temperature, in which latter case the durationof contact between cotton and acid may not exceed 20 seconds. i

pieces are then dipped into the same dyebath, the first piece will prove to have been dyed to a considerably darker color than the second piece, which is another advantage of the use of cold sulfuric acid.

If a cotton fabric is dipped, for a period of several minutes, into sulfuric acid at'a low temperature, then washed and dried without being stretched, the fabric will become of a wool-like appearance. Up to now, working at normal temperature, such a result could be obtained with sulfuric acid of BJ-51 B., only if the cotton treated had undergone a preliminary mercerization or else was subsequently submitted to the ac-. tion' of lye and dried without being stretched. 1

It is obvious that by means of suitably ap-. plied reserves, the action of the cold sulfuric acid might be localized, and patterns obtained. In this case the use of cold acid is especially advantageous, as its action on the reserve coating Wlll be less intense than could be the case with acid of higher concentration and at normal temperature, so that the resulting pattern has a clearer outline.

Thus, by using a reserve with the acid treatment and subsequent mercerization and stretching of the fabric, a pattern of transparent places on a nontransparent ground may be obtained, while if used with the acid treatment alone, places of Woolly appearance will result on a smooth ground.

These patterns may be dyed, when the effect will be still more enhanced, as the parts of thefabric that have been under the action of sulfuric acid will take a deeper stain with most dyes. v

Having now particularly described and ascertained the nature of the. said invention and in what manner the same is to be performed, I declare that what I claim is:

1. Process for the treatment of cotton fabrics, comprisin subjecting the fabric to the action of s 50.50 B., at a temperature considerably below 0 0., and subsequently treating the fabric with lye of about 0 0., and stretching it, to obtain transparency of the fabric.

2. Process for the treatment of cotton fabrics, comprisin subjecting the fabric to the action of s furic acid of less than 50.50 B., at a temperature considerably below 0. (3., in combination with a reserve, and thereafter treating the fabric with lye at a temperature of about 0 0., and stretching it to obtain transparent patterns.

furic acid of less than 3. A step in the process for the treatment of cotton fabrics, which comprises treating the fabric with a cold sulfuric acid solution of a concentration less than 50.50 B.

and below 0 C.

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribmg witnesses.

OSCAR KL'AUSER.

Witnesses:

FRANK DINUNKE, EMIL WEILE'. 

